Making your own insecticide is less expensive and you can be sure you are not adding harmful chemicals to the environment.

Insecticidal Soap. Easy and inexpensive to make.  Use ordinary all-soap dishwashing liquid.  Ivory is a good choice and many prefer Dawn.  Do not use detergents.  Check the label as many dish soaps now contain a lot of additives including Oxi-clean which is great on stains but not needed for an insecticide.

Add 1 tablespoon  (15 ml) or soap to 1 gallon (4 litres) of water and spray everything.  It won’t hurt the lawns, the foliage, nor the flowers.  And it works.  I’ve used it to wipe out all sorts of bothersome pests.  This actually helps clean up your garden in more than one way.  The spray upsets the innards of the local insect population but it also cleans off pollutants from the surfaces of the plants.

Other Insecticides

• Used cooking water from asparagus kills bad nematodes and protects the roots and leaves of tomatoes. 
  Notes: Bad nematodes can cause issues with your vegetables and fruit trees. These include: Root knot nematode, Root lesion nematodes, Dagger nematodes, and Ring and spiral nematodes.  There are also beneficial nematodes which you should mix with water and spray into your lawn to kill off grubs! 
• Antifungal garlic/onion spray will help control disease and insect pests. Try the following:  Add either 2 handfuls of chopped green onions or 4 cloves or garlics – smashed up a bit - to boiling water.  Do not put a lid on the water. Boil for 5 minutes the add ½ cup (125ml) of this onion/gardlic water to 5 gallons (*20litres) of a good fertilizer to make a “fertilizer tea” which can be sprayed on your plants.
• Attract Beneficial Insects. Some insects are beneficial to the health of your plants. Examples include ladybugs, parasitic wasps, and lacewing flies.  You want to attract these insects to your garden so they can help control insects for you. They will be attracted to your garden if you spray your plants with the following. Mix 2 Tablespoons of brewer’s yeast, ¼ cup of sugar, 1 tsp of honey, and 1/3 cup of warm water. Mix the ingredients together.  To use, take 1 tablespoon of your mixture add it to 2 cups of water and use that to spray the plants in spring and early autumn to attract the beneficial bugs. 
• Slugs. To kill slugs, you can also use the “attracting” spray mixture just mentioned. Set it out in small containers on the ground to attract slugs which will drink it then die.  ☹